Switchable silent ratchet

Abstract

A switchable clamp-type locking mechanism with an output shaft ( 3 ) that rotates in relation to a housing ( 1 ) is provided. Furthermore, clamping elements, in particular clamping balls or clamping rollers ( 4 ) are provided that are pushed by a spring force into a clamping gap ( 16 ) in their clamped position and are confined by a smooth track ( 15 ) on the housing ( 1 ) and by locking ramps ( 13, 14 ) on the output shaft ( 3 ). A drive shaft ( 2 ) to rotate the output shaft ( 3 ) is provided. The clamping elements are moved into a release position using a device by means of which the clamping elements are freed to rotate the output shaft ( 3 ). A slide ( 7 ) that is fixed to the output shaft ( 3 ) is form-locked to the housing ( 1 ) in the clamped position of the clamping elements and is disengaged from the housing ( 1 ) in the release position of the clamping elements.

What is claimed is:  
     
       1. A switchable clamp locking mechanism comprising an output shaft ( 3 ) that rotates with respect to a rotatably fixed part, comprising a housing ( 1 ), with clamping elements, formed from clamping rollers ( 4 ), that are pushed by a spring force into a clamping gap ( 16 ) in a clamped position, and are confirmed by a smooth track ( 15 ) on the rotatably fixed part and by locking ramps ( 13 ,  14 ) on the output shaft ( 3 ), a drive shaft ( 2 ) to turn the output shaft ( 3 ) and a device to move the clamping elements into a released position in which the clamping elements are released to allow the output shaft ( 3 ) to turn, a slide ( 7 ) connected to the output shaft ( 3 ) is locked to the rotatably fixed part in the clamped position and is disengaged from the rotatably fixed part in the released position of the clamping elements. 
     
     
       2. A switchable clamp locking mechanism according to  claim 1 , wherein a device is located between the drive shaft ( 2 ) and the slide ( 7 ) to convert a rotational motion of the drive shaft ( 2 ) into a longitudinal shift of the slide ( 7 ). 
     
     
       3. A switchable clamp locking mechanism according to  claim 1 , wherein a ramp ( 20 ,  21 ) is provided on the slide ( 7 ) and an attachment is located on the drive shaft ( 2 ) for the ramp ( 20 ,  21 ) at a distance from an axis of the output shaft ( 3 ). 
     
     
       4. A switchable clamp locking mechanism according to  claim 3 , wherein the radially movable slide is provided with a triangular cutout ( 11 ) perpendicular to the drive shaft ( 2 ), and two adjacent walls of the triangular cutout each form one ramp ( 20 ,  21 ). 
     
     
       5. A switchable clamp locking mechanism according to  claim 1 , in which the slide ( 7 ) is radially movable inside a guide ( 9 ). 
     
     
       6. A switchable clamp locking mechanism according to  claim 1 , wherein the slide ( 7 ) is disengagable from the rotatably fixed part against a spring force of a spring ( 10 ). 
     
     
       7. A switchable clamp locking mechanism according to  claim 1 , wherein the slide ( 7 ) includes teeth ( 8 ) and the rotatably fixed part is formed as a housing ( 1 ) that includes teeth ( 6 ) that engage with each other to produce a form-locked connection.